Nitrite oxidoreductase(NXR) is the key enzyme responsible for the oxidation of NO2-to NO3-in nitrite-oxidizing bacteria.Since NXR is a dissoluble enzyme,located at the inner side of the membranes of cells,its function is dependent on the electron transfer chain related to membranes.This paper reviews the advances in study on NXR,including the structure,catalysis mechanism and the impact of different factors.New techniques applied in recent studies and research prospects are also presented.

Objective To investigate the resistant mechanism of imipenem-resistant K. pneumoniae.Methods The minimal inhibitive concentrations (MICs) of the antimicrobial agents were determined by Etest.Isoelectric focusing electrophoresis (IEF),plasmid extraction,conjugation, transformation,PCR amplification,cloning and sequencing were carried out for analyzing the encoding gene of ?-1actamases.Results Three kinds of ?-1actamases were detected with pIs of 7.2,6.7,and 5.4.in a clinical strain of K.pneumoniae.These ?-1actamases were TEM-I (pI,5.4),SHV-12 (pI,8.2) and KPC-2 ( pI,6.7 ) confirmed by sequencing of the PCR products.Only one band of ?-1actamase with pI 6.7 was displayed in the transformant.A 1500 bp segment,which contained the KPC-2 gene confirmed by nucleotide sequence analysis,was cloned from a 60 000 bp plasmid of the transformant.Conclusion The strain of K.pneumoniae resistant to imipenem produces a plasmid-mediated carbapenemase KPC-2 which belongs to Bush group 2f,class A ?-1actamase.

Objective: To investigate the effect of taurine on learning and memory impairment, cytokines secretion in rats intrahippocampally injected with ?-amyloid (A?) 1-40. Methods: SD rats were randomly divided into control group, A? injected group, taurine (0.3g/kg?d, 0.6g/kg?d) groups. The rats were fed with taurine for 7 days, and then subjected to bilateral intrahippocampus injection of A?1-40 or vehicle. Two weeks later, all rats performed Morris water maze test. The contents of IL-6, TNF-? were checked by way of radio-immunity assay for hippocampus samples. Results: Compared with A?model group, the escape latency and distance were significantly reduced in taurine (0.6g/kg?d) group; the ratio of swimming distance in the target quadrant to that in the whole pool of the probe trial; the content of cytokines of IL-6 and TNF-?in hippocampus were reduced significantly. Conclusion: Taurine can effectively attenuate the cognitive dysfunction caused by A?1-40 in rats. The reduced cytokines content in hippocampus might contribute to this effect.

Objective:To observe the effect of liver-soothing and mind-regulating acupuncture method on the resting-state electroencephalography (EEG) in rats with post-traumatic stress disorder (PTSD),and to provide evidence for the effect mechanism study and clinical application of acupuncture intervention for PTSD.Methods:Sixty Sprague-Dawley (SD) rats were randomly divided into a blank control group,a model group,a grasping group,a paroxetine group and an acupuncture group,with 12 rats in each group.Except for rats in the blank control group,rats in the other groups were subjected to preparing the PTSD models using 'incarceration plus electric shock' method.After interventions,changes in rat behavior of each group were observed;changes in resting-state EEG were collected and analyzed with multichannel EEG acquisition and analysis system,and image analysis and statistical processing were performed.Results:Compared with the blank control group,the average escape latency in the model group was significantly longer (P＜0.05),and the times of crossing the platform and the effective areas were all significantly reduced (P＜0.01).Compared with the grasping group,the average escape latencies in the paroxetine group and acupuncture group were significantly shortened (P＜0.05),and the times of crossing the platform and the effective areas were all significantly increased (P＜0.05).There were no significant differences in the average escape latency,the times of crossing the platform and the effective areas between the acupuncture group and paroxetine group (all P＞0.05).Compared with the blank control group,the α-wave power spectrum value in the model group was significantly decreased,and the power spectrum values of β-wave,δ-wave and a-wave were significantly increased (all P＜0.01);compared with the grasping group,α-wave power spectrum values in the paroxetine group and acupuncture group were significantly increased (both P＜0.01),and the power spectrum values of β-wave,δ-wave and a-wave were decreased significantly (all P＜0.01).The power spectrum values of α-wave,β-wave,δ-wave and (e)-wave of rats in the acupuncture group were not significantly different from those in the paroxetine group (all P＞0.05).Conclusion:Liver-soothing and mind-regulating acupuncture method can significantly improve the abnormal EEG activity in PTSD rats,which may be one mechanism of liver-soothing and mind-regulating acupuncture method in effectively affecting the brain function in PTSD rats.

Objective To compare effection of two kinds of bowel preparation for enteroscopy in aged patients. Methods 100 patients who would receive enteroseopy were divided into two groups. 50 cases in each group. Patients in experimental group received colon dialysis, patients in control group received oral medication. Observed the effectiveness of two kind of bowel preparations and adverse reaction. Results The effectiveness of colon dialysis was superior to oral medication(P <0. 05) ,there was no significant deviation the adverse reaction of two groups. Conclusions Colon dialysis is a suitable method in bowel preparation for enteroscopy in aged patients.

Objective To investigate the expression of peroxisome proliferator-activated receptor (PPAR?)in lupus nephritis(LN)patients and the possible mechanisms of PPAR?in the pathogenesis of LN. Method PPAR?expression was examined in 21 LN patients and 5 normal kidney biopsy specimens by im- munohistochemical method.The relationship between PPAR?expression and renal pathologic changes was an- alyzed.Results Glomerular and tubular positive staining of PPAR?in LN patients was markedly up-regulated compared with that in normal kidney specimens.The distribution and expression of PPAR?in classⅣwas sig- nificantly increased compared with that in classⅤandⅡ.The relevance assay showed that there was positive relationship between active index and glomerular PPAR?immunohistochemistry staining cell numbers(r=0.94, P＜0.01 ).Conclusion This study demonstrates in vivo that PPAR?expression is increased in active LN pa- tients with pathological active inflammation.These data suggest that the increase of PPAR?expression in renal cells may play an important role in the pathogenesis of LN.

OBJECTIVETo study and evaluate the curative effect and mechanism of Qiangxin Granule (QXG) in intervening chronic heart failure (CHF) rats with Xin-qi deficiency complicated blood stasis and edema syndrome (XQD-BS-ES).

METHODSTotally 72 SD rats of clean grade were randomly divided to the normal control group (n =10) and the model group (n = 62). The XQD-BS-ES rat model was established by adriamycin plus propylthiouracil method. Survived modeled rats were then randomly divided to 5 groups i.e., the model group (n = 11, administered with normal saline by gastrogavage), the Western medicine (WM) group (n =11 , administered with perindopril and hydrochlorothiazide by gastrogavage), the low dose QXG (QXG(L)) group (n = 11, administered with 9.26 g/kg QXG by gastrogavage), the middle dose QXG (QXG(M)) group (n = 11, administered with 18.52 g/kg QXG by gastrogavage), the high dose QXG (QXG(H)) group (n = 11, administered with 37.04 g/kg QXG by gastrogavage). After 4 weeks of treatment, left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), brain natriuretic peptide (BNP), heart rate (HR), respiratory rate (RR), urine output, ear temperature, exhaustive swimming test (EST), tri-iodothyronine (T3), tetra-iodothyronine (T4), thyroid stimulating hormone (TSH), as well as heart, lung, liver weight index and their pathological sections, and high sensitivity C-reactive protein (HS-CRP), angiotensin II (Ang II), carbohydrate antigen 125 (CA125) were detected and compared.

RESULTSCompared with the normal control group, LVEF, LVFS, BNP, HR, RR, urine output, ear temperature, EST, T3, T4, TSH, HS-CRP, Ang II, and CA125 changed significantly in the model group (P < 0.01). Compared with the model group after treatment, LVEF, LVFS, BNP, urine output, EST, T4, heart and liver weight index, HS-CRP, Ang II, CA125 were significantly improved in each QXG group (P < 0.05, P < 0.01). Moreover, TSH was improved in the QXGL and QXG(M) groups (P < 0.05); ear temperature and T3 in the QXG(M) were also improved (P < 0.05); the lung weight index decreased in the QXG(M) and QXG(H) groups (P < 0.01). Compared with the WM group, T4 and CA125 were obviously improved in all QXG groups (P < 0.01); BNP and ear temperature were obviously improved in QXG(L) and QXG(M) groups (P < 0.05, P < 0.01); LVEF, LVFS and TSH were obviously improved in the QXG(M) group (P < 0.05, P < 0.01). And as far as each treatment group, LVEF, LVFS, urine output increased significantly after treatment (P < 0.01); EST obviously increased in QXG(M) and QXG(H) groups (P < 0.01); ear temperature increased in all QXG groups (P < 0.05, P < 0.01). Moreover, compared with the model group, pathological changes of heart, lung, and liver were improved to some degree in each treatment group, especially in the QXG(M) group.

CONCLUSIONSGood curative effect was shown in each QXG group. QXG could improve LVEF, LVFS and BNP of CHF rats of XQD-BS-ES, as well as T3, T4, TSH, EST, urine output, and ear temperature. Moreover, QXG showed superiority than WM group in this respect.

Angiotensin II ; Animals ; C-Reactive Protein ; Chronic Disease ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Edema ; Heart ; Heart Failure ; drug therapy ; Heart Ventricles ; Medicine, Chinese Traditional ; Natriuretic Peptide, Brain ; Qi ; Rats ; Rats, Sprague-Dawley ; Syndrome ; Thyrotropin ; Ventricular Function, Left

The purpose of this study was to determine the effect of nitric oxide (NO) in the rostral ventrolateral medulla (RVLM) on the central integration of the cardiac sympathetic afferent reflex (CSAR) in normal rats and in rats with coronary ligation-induced chronic heart failure (CHF). Under alpha-chloralose and urethane anesthesia, mean arterial pressure, heart rate and renal sympathetic nerve activity (RSNA) were recorded at baseline and during elicitation of the CSAR evoked by electrical stimulation of the cardiac afferent sympathetic nerves in sino-aortic denervated and cervical vagotomized rats. A cannula was inserted into the left RVLM for microinjection of NO synthase inhibitor, S-methyl-L-thiocitruline (MeTC) or NO donor, S-nitroso-N-acetyl-penicillamine (SNAP). The CSAR was tested by electrical stimulation (5, 10, 20 and 30 Hz at 10 V for 1 ms) of the afferent cardiac sympathetic nerves. It was observed that (1) the responses of RSNA to stimulation were enhanced in rats with CHF; (2) MeTC (80 nmol) potentiated the responses of RSNA to stimulation in sham rats but not in rats with CHF; (3) SNAP (50 nmol) depressed the enhanced RSNA response to stimulation in CHF rats but had no effect in sham rats; and (4) MeTC increased the baseline RSNA and MAP only in sham rats, but SNAP inhibited the baseline RSNA and MAP in both sham and CHF rats. These results indicate that reductance of NO in the RVLM is involved in the augmentation of CSAR in CHF rats.
Afferent Pathways ; physiopathology ; Animals ; Heart Failure ; physiopathology ; Male ; Medulla Oblongata ; physiopathology ; Nitric Oxide ; metabolism ; physiology ; Rats ; Rats, Sprague-Dawley ; Reflex ; physiology ; Sympathetic Nervous System ; drug effects ; physiopathology

OBJECTIVETo establish a rapid specific method to identify the single-nucleotide polymorphisms (SNPs) of HBV polymerase gene region which are the methionine residue of the conserved YMDD motif.

METHODSTwo specific primers were designed to amplify interested gene region involved in SNPs which were also used as HBV DNA identification. Specific primers of SNaPshot were designed to detect 741A-G (YVDD), 743G-T (YIDD). The different fluorescent dye labeled ddNTP was used to further extend the strand of PCR product and was detected by ABI PRISM 310 Genetic Analyzer. Sera from 13 patients with chronic hepatitis B after lamivudine treatment were analyzed.

RESULTSAside from mutation of YMDD, there were mutations of 514C-A, 523C-A, 562T-A, 667C-A. The 13 samples were simultaneously tested with SNaPshot and DNA sequencing, the same results were obtained. The method of SNaPshot showed high specificity.

CONCLUSIONMutation of YMDD results in the changes of ATG codon, and there are new ATG codon in the upper strand of YMDD. SNaPshot technique is rapid, specific and accurate for the SNPs monitoring of HBV DNA mutation during lamivudine therapy. Two samples were determined by SnaPshot technique, identifying the co-existence of the mixed wild type and mutant type HBV infection.

Antiviral Agents ; therapeutic use ; Base Sequence ; DNA, Viral ; blood ; genetics ; Drug Resistance, Viral ; Gene Products, pol ; genetics ; Hepatitis B ; blood ; drug therapy ; virology ; Humans ; Lamivudine ; therapeutic use ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA

OBJECTIVETo study the rehabilitation effects ergometry on COPD patients.

METHODSThirty COPD out-patients in our Hospital were randomly divided into 2 groups. Rehabilitation group, 15 patients, performed leg ergometry exercise of 80% peak Watt x 30min/d x 3d/w x 12w. Another 15 patients were control group without exercise. All patients received conventional therapy. Pulmonary function testing (PFT), cardiopulmonary exercise testing (CPET), arterial blood gas analysis (ABG), Borg and CAT sores were done at both baseline and 12 w.

RESULTSThere was no statistically difference in lung function testing, blood gas analysis and cardiopulmonary exercise test when pre- exercises between 2 sub-groups. The IC, peak VO2 and peak, W of rehabilitation group significantly increased (P < 0.05); and Borg and CAT.scores significantly decreased (P < 0.05) from baseline; and other PFT and ABG did not change (P > 0.05). While there was no difference in control group (P > 0.05).

CONCLUSIONLeg submaximal ergometry rehabilitation improves health condition and ameliorate dyspnea symptoms in COPD patients.

Blood Gas Analysis ; Dyspnea ; therapy ; Exercise Test ; Exercise Therapy ; Humans ; Pulmonary Disease, Chronic Obstructive ; therapy ; Respiratory Function Tests